How much cam for 7000rpm?
08-08-2015, 12:27 PM
#1
How much cam for 7000rpm? Been talking to a few cam vendors about doing a cam that will pull to 7000rpm in my LS2. Figured that wouldn't be too hard given the stock redline is 6500 with the tinsy OEM cam and heads.
Top end will include some ported 243 heads by AI and a FAST 102 manifold along with the supporting lifters/springs/pushords etc. The cam most people spec'd was in the low-mid 230s duration with some 10-14* of overlap. I was hoping to stay with a slightly milder cam for endurance racing but was told that anything smaller than that would have a hard time pulling to 7000rpm.
Is it just me or does that seem a little extreme? I didn't think 7000rpm was such a lofty goal that would require so much cam. Figured with ported heads, big FAST intake it wouldn't take too much more cam to go from the stock redline of 6500 to 7000. But it seems that little jump requires a decent cam...
Anyone else have some examples of what kind of cam would peak around 6700 for the shift to be at 7000?
Top end will include some ported 243 heads by AI and a FAST 102 manifold along with the supporting lifters/springs/pushords etc. The cam most people spec'd was in the low-mid 230s duration with some 10-14* of overlap. I was hoping to stay with a slightly milder cam for endurance racing but was told that anything smaller than that would have a hard time pulling to 7000rpm.
Is it just me or does that seem a little extreme? I didn't think 7000rpm was such a lofty goal that would require so much cam. Figured with ported heads, big FAST intake it wouldn't take too much more cam to go from the stock redline of 6500 to 7000. But it seems that little jump requires a decent cam...
Anyone else have some examples of what kind of cam would peak around 6700 for the shift to be at 7000?
08-08-2015, 03:59 PM
#2
TECH Apprentice
Been talking to a few cam vendors about doing a cam that will pull to 7000rpm in my LS2. Figured that wouldn't be too hard given the stock redline is 6500 with the tinsy OEM cam and heads.
Top end will include some ported 243 heads by AI and a FAST 102 manifold along with the supporting lifters/springs/pushords etc. The cam most people spec'd was in the low-mid 230s duration with some 10-14* of overlap. I was hoping to stay with a slightly milder cam for endurance racing but was told that anything smaller than that would have a hard time pulling to 7000rpm.
Is it just me or does that seem a little extreme? I didn't think 7000rpm was such a lofty goal that would require so much cam. Figured with ported heads, big FAST intake it wouldn't take too much more cam to go from the stock redline of 6500 to 7000. But it seems that little jump requires a decent cam...
Anyone else have some examples of what kind of cam would peak around 6700 for the shift to be at 7000?
Top end will include some ported 243 heads by AI and a FAST 102 manifold along with the supporting lifters/springs/pushords etc. The cam most people spec'd was in the low-mid 230s duration with some 10-14* of overlap. I was hoping to stay with a slightly milder cam for endurance racing but was told that anything smaller than that would have a hard time pulling to 7000rpm.
Is it just me or does that seem a little extreme? I didn't think 7000rpm was such a lofty goal that would require so much cam. Figured with ported heads, big FAST intake it wouldn't take too much more cam to go from the stock redline of 6500 to 7000. But it seems that little jump requires a decent cam...
Anyone else have some examples of what kind of cam would peak around 6700 for the shift to be at 7000?
08-08-2015, 08:02 PM
#4
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I fitted a CompCam 235 243 .621" .624" 113 to friends manual HSV GTO.
Pulls surprisingly well down low whilst at the track I shift gears past 7,000rpm and cross the line at up to 115mph in third gear.
Pulls surprisingly well down low whilst at the track I shift gears past 7,000rpm and cross the line at up to 115mph in third gear.
08-08-2015, 08:28 PM
#5
Most after market cam will turn 7000 even the stock cam will. The question is how much power do you want at 7000? If you want peak power there you will need a cam much larger than the 230s maybe even the high 240s or low 250s depending on many other factors.
Just wanted to be able to shift at 7000 based on the track and gearing layout that I have, helping get more out of each gear and having less shifts overall. So something that peaks mid 6000s I imagine. As long as it doesn't fall on its face past 6500 that's all that matters.
08-09-2015, 12:40 AM
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I don't want peak power there because at that point I'd need to shift at 74-7500 or so which I don't think is going to work without some fancy valvetrain.
Just wanted to be able to shift at 7000 based on the track and gearing layout that I have, helping get more out of each gear and having less shifts overall. So something that peaks mid 6000s I imagine. As long as it doesn't fall on its face past 6500 that's all that matters.
Just wanted to be able to shift at 7000 based on the track and gearing layout that I have, helping get more out of each gear and having less shifts overall. So something that peaks mid 6000s I imagine. As long as it doesn't fall on its face past 6500 that's all that matters.
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08-09-2015, 06:51 AM
#8
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08-09-2015, 11:58 AM
#9
Shifting above peak power Hmm for best track results (lower elapse times) shift point would be somewhere between peak torque and peak horse power.
08-10-2015, 12:35 AM
#12
